libpod: honor runtime_path from libpod.conf

Add backward compatibility for `runtime_path` that was used by older
versions of Podman.

The issue was introduced with: 650cf122e1b33f4d8f4426ee1cc1a4bf00c14798

If `runtime_path` is specified, it overrides any other configuration
and a warning is printed.

It should be considered deprecated and will be removed in future.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/libpod/runtime.go b/libpod/runtime.go
index b01674be0..4f5d1e292 100644
--- a/libpod/runtime.go
+++ b/libpod/runtime.go
@@ -130,6 +130,12 @@ type RuntimeConfig struct {
 	OCIRuntime string `toml:"runtime"`
 	// OCIRuntimes are the set of configured OCI runtimes (default is runc)
 	OCIRuntimes map[string][]string `toml:"runtimes"`
+	// RuntimePath is the path to OCI runtime binary for launching
+	// containers.
+	// The first path pointing to a valid file will be used
+	// This is used only when there are no OCIRuntime/OCIRuntimes defined.  It
+	// is used only to be backward compatible with older versions of Podman.
+	RuntimePath []string `toml:"runtime_path"`
 	// ConmonPath is the path to the Conmon binary used for managing
 	// containers
 	// The first path pointing to a valid file will be used
@@ -403,6 +409,7 @@ func NewRuntime(options ...RuntimeOption) (runtime *Runtime, err error) {
 			runtime.config.ConmonPath = tmpConfig.ConmonPath
 			runtime.config.ConmonEnvVars = tmpConfig.ConmonEnvVars
 			runtime.config.OCIRuntimes = tmpConfig.OCIRuntimes
+			runtime.config.RuntimePath = tmpConfig.RuntimePath
 			runtime.config.CNIPluginDir = tmpConfig.CNIPluginDir
 			runtime.config.NoPivotRoot = tmpConfig.NoPivotRoot
 			break
@@ -485,10 +492,25 @@ func NewRuntimeFromConfig(configPath string, options ...RuntimeOption) (runtime
 // Make a new runtime based on the given configuration
 // Sets up containers/storage, state store, OCI runtime
 func makeRuntime(runtime *Runtime) (err error) {
+
+	// Backward compatibility for `runtime_path`
+	if runtime.config.RuntimePath != nil {
+		// Don't print twice in rootless mode.
+		if os.Geteuid() == 0 {
+			logrus.Warningf("The configuration is using `runtime_path`, which is deprecated and will be removed in future.  Please use `runtimes` and `runtime`")
+			logrus.Warningf("If you are using both `runtime_path` and `runtime`, the configuration from `runtime_path` is used")
+		}
+
+		// Transform `runtime_path` into `runtimes` and `runtime`.
+		name := filepath.Base(runtime.config.RuntimePath[0])
+		runtime.config.OCIRuntime = name
+		runtime.config.OCIRuntimes = map[string][]string{name: runtime.config.RuntimePath}
+	}
+
 	// Find a working OCI runtime binary
 	foundRuntime := false
 	// If runtime is an absolute path, then use it as it is.
-	if runtime.config.OCIRuntime[0] == '/' {
+	if runtime.config.OCIRuntime != "" && runtime.config.OCIRuntime[0] == '/' {
 		foundRuntime = true
 		runtime.ociRuntimePath = OCIRuntimePath{Name: filepath.Base(runtime.config.OCIRuntime), Paths: []string{runtime.config.OCIRuntime}}
 	} else {